Letters in Finnish

The letters used in Finnish texts can be classified
as follows, roughly in descending order by conventionality and
familiarity:

The letters that are needed for writing purely
and originally Finnish words:
a, d, e, g, h, i, j, k, l, m, n, o, p, r, s, t, u, v, y, ä, ö.
Among these, d is somewhat special, since it has been intentionally
introduced into standard Finnish.
There is no acceptable way to dispense with ä and ö in Finnish texts.
In particular, the convention (used in German for example) of replacing
them by ae and oe is not acceptable for Finnish, although this
replacement method is generally known by Finns due to its application
in international texts.

Letters that appear often in (relatively new) loanwords:
b, f.

Base letters that are conventionally regarded as part of the Finnish
alphabet, yet appear only in words of foreign origin that have exceptionally
preserved their original spelling and, naturally, in foreign names, and
derivations of such words:
c, q, w, x, z, å.

The letters š and
ž. They are officially regarded
as part of Finnish orthography, although they occur relatively rarely
and only in loanwords, foreign names, and their derivations and
although they are often omitted when listing the Finnish alphabet.
For the official position, see
Finnish orthography and the characters s caron
and z caron.
However, in newspapers, informal texts, and even in many books, these
letters are very often replaced by the letter pairs sh and zh,
respectively, or, less often, the diacritic is omitted.

Letters that appear relatively often in names of foreign origin,
their derivations, or loanwords that have been taken directly from
another language (foreign words, Finnish sitaattilaina).
This group is difficult to specify, but it is
probably adequate to count at least the following letters:

é appears often in names, including names of Finnish citizens
(e.g., Lindén), and also in foreign words like
moiré

á in names, though less often (e.g., Collán)

à in the French preposition à, which is
used not uncommonly
in Finnish to indicate a range or a unit price

ü especially in names and foreign words of German (or Estonian)
origin, including surnames used in Finland, like Schüler

ñ in foreign words like mañana

ç sometimes in foreign words like
garçon

ß in names of German origin; not commonly used, but
probably recognized relatively well.

ë in scientific names of organisms, though the
dieresis is often omitted.

The letters æ and ø due to their frequency
in Norwegian and Danish names. Probably often replaced by ä and ö,
respectively.

The letter õ due to its appearance in Estonian names.
Probably often confused with ö.

Other Latin letters that appear relatively often in names,
but hardly in foreign words. The diacritics used in these letters
are omitted far more often than for the previous group, and
readers may fail to notify the diacritics.
This group too is hard to list down, but it might be regarded as containing
the following Latin letters:
ã,
í, ó, ú, ý,
è, ì, ò, ù,
â, ê, î, ô, û,
ï, ÿ.
(These are the letters with diacritic that belong to ISO Latin 1
and have not been listed above. Among these, those commonly used in French
and Italian, such as è, are probably
more widely used and recognized than the rest.)

The additional letters used in the Northern Sámi language:
č,
đ,
ŋ,
ŧ.
They appear in personal, geographic,
and company names in Finland relatively often in Northern Finland.
Since they
are often unavailable in
fonts and difficult to produce on keyboards, it is common
(but not correct)
to omit the diacritic.

The additional letters used in other Sámi languages spoken in Finland:
ʒ,
ǥ,
ǧ,
ǩ,
ǯ.

Letter
ȟ
(h with caron),
which is used in the Romani
language spoken in Finland.
It is rarely used,
since it is usually
unavailable in currently available
fonts and difficult to produce on keyboards.

The letters
ð and þ (used e.g. in Icelandic)
which are classified as Latin letters and available in the
ISO Latin 1 repertoire but not widely recognized in Finland.
In Icelandic names, they are often replaced by d (or dh) and th,
respectively.

Combinations of Latin letters a–z with diacritic
marks not listed above, such as ć
(c with acute, used e.g. in Croatian).
In actual practice in Finland,
these are
very often written without the diacritic mark.
These, and characters in
the following classes, only appear in proper names
and literal quotations.
Among these characters, those that appear in official languages of
the European Union
(especially Polish, Lithuanian, and Latvian)
can be expected to be, or to become, more common
and widely recognized than the rest.
The distinction drawn here between this group and the preceding group
is largely based on technical considerations such as the widespread
support to ISO Latin 1 repertoire in software used in Finland.

Other letters classified as Latin letters in the broad
sense, such as
ə (used in Azeri).

Letters used in non-Latin writing systems,
such as Cyrillic or Greek. These occur basically in scientific texts
only, mostly in linguistics (in the rare cases when transliteration
or transcription is not used) and in mathematical and
scientific notations.
The only such letter in common use is Ω, which is used
as the ohm symbol in the international system of units; however
first few lowercase letters of the Greek alphabet,
α, β, γ etc.,
might be seen even in newspaper texts (in astronomical, chemical,
and other terms).

Notes

Historical note:
In a book on Finnish phonetics and orthography,
Suomen kielen äänne- ja oikeinkirjoitusoppi
(published in 1949),
Aarni Penttilä wrote about
the alphabetic order as consisting of
“a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s,
(š), t, u, v, x, y (ü), z, (ž), å, ä, ö (ø), (õ)”.
According to him, this list constitutes the
“Finnish-Swedish alphabet”
(“suomalais-ruotsalainen aakkosto”)
when the letters in parentheses are omitted.
He described the letter w essentially as an allograph of v and as
a holdover from Gothic fonts.

This document does not discuss the use and recognizability
of compatibility characters that are classified as letters or as
compatibility equivalent to a letter. For example, the masculine
ordinal indicator º is technically a letter.

For links to some material on the Finnish language on the Internet,
please check my page
The Finnish language.